DESCRIPTION: (Applicant's Abstract) In 1996, the Drug Abuse Warning Network (DAWN) estimated 14 percent of all drug-related emergency department episodes in the United States were heroin involved. In December 1997, the National Institute on Drug Abuse, Division of Epidemiology and Prevention, Community Epidemiology Work Group (CEWG) reported heroin was the primary drug of abuse of San Francisco's drug treatment program admissions. In this application, we propose to conduct an ethnographic investigation into the initiation and continuation practices of new heroin users in the San Francisco Bay Area. Employing ethnographic sampling techniques, we will recruit and enroll 120 participants, 18 to 25 years old, who have used heroin five or more times in the previous 30 days. Half of the proposed sample will be women (60) and half men (60), and we will further stratify the sample according to respondents' self-identified primary route of administration: (40) injectors, (40) smokers and (40) intranasal users. During qualitative (tape recorded) life history interviews with each respondent, we will focus on the following research topics: (1) the process of initiation into heroin-using social worlds; (2) the factors which influence progression to continued heroin use; (3) the process of changing (or not changing) routes of administration; (4) the ways in which young heroin users manage their heroin, and other drug use and everyday life activities; (5) participants' heroin purchasing practices types/levels of criminal involvement; (6) younger heroin users' perceptions of and attitudes toward drug-related health risks, as well as their a~al high-risk behaviors; and, (7) the impact of social networks on initiation and continuation of heroin use. The products of this research will include: (A) An exploration of the processes of initiation and continuation among young heroin users in the San Francisco Bay Area. (B) Essential information for service providers and policy makers interested in creating efficacious interventions targeted for this growing group of new heroin users. And, (c) pilot work for a large scale study that can test emergent hypotheses with a control group.